Gearshift for dual derailleur bicycle

Abstract

A dual derailleur bicycle gearshift comprises a first cable pull member pivotally secured to a support for rotation about a first axis and a second cable pull member pivotally secured to the first cable pull member for rotation about a second axis perpendicular to the first axis, wherein the second cable pull member defines a single actuator that is centered on both axes for pivotal movability within a first arc located within a first plane that extends axially of and contains the first axis to rotate the second cable pull member about the second axis and pivotal movability within a second arc located within a second plane that extends axially of and contains the second axis to rotate the first cable pull member about the first axis. In a handlebar mounted embodiment the first cable pull member rotates about a longitudinal axis of the bicycle's handlebar and the actuator is a yoke centered on both axes and having one end defining the second cable pull member. In a handlebar stem mounted embodiment the actuator is a lever and the first cable pull member is notched for centering the lever on both axes. In each embodiment a first bracket member stationary with the support provides anchorage for a casing associated with a cable pulled by the first cable pull member, and a second bracket member rotatable with the first cable pull member provides anchorage for a casing associated with a cable pulled by the second cable pull member.

I claim: 
     
       1. A gearshift for use on a bicycle that has multiple front sprockets mounted on a pedal crank axis, multiple rear sprockets mounted on a rear wheel axis, a roller chain forming a closed loop about and connecting together one each of said front and rear sprockets, a front derailleur and a rear derailleur associated with said front and rear sprockets and movable axially of said pedal crank and rear wheel axes into given front and rear sprocket alignment positions for positioning said roller chain on said front and rear sprockets, respectively, and a pair of cables connected one each to said derailleurs for effecting said axial movement of said derailleurs in response to linear movement of said cables, said bicycle including cable guide means arranged between said derailleurs and free ends of said cables for restricting said cables to said linear movement; said gearshift comprising: support means attachable to said bicycle in fixed position;   a first cable pull member pivotally secured to said support means for rotation about a first axis, said first cable pull member being adapted to secure the free end of a first one of said cables for effecting linear movement of said first one of said cables by rotation of said first cable pull member about said first axis;   a second cable pull member pivotally secured to said first cable pull member for rotation about a second axis perpendicular to said first axis, said second cable pull member being adapted to secure the free end of the other one of said cables for effecting linear movement of said other one of said cables by rotation of said second cable pull member about said second axis;   said second cable pull member defining a manually operable actuator centered on said first and second axes for pivotal movability within a first arc located within a first plane that extends axially of and contains said first axis to rotate the second cable pull member about said second axis and for pivotal movability within a second arc located within a second plane that extends axially of and contains the said second axis to rotate said first cable pull member about said first axis; and,   means for holding said first and second cable pull members at rotational settings.   
     
     
       2. A gearshift as in claim 1 wherein said first cable pull member is provided with a notch defined between first and second end portions of said first cable pull member, said first axis passes through said first and second end portions, said second axis is located in said notch between said first and second end portions and one of said end portions is adapted to secure said free end of said first one of said cables, and wherein said actuator is a lever having a manually graspable upper end portion aligned with said first axis for pivotal movability within said first arc and having a lower end portion defining said second cable pull member, said second cable pull member being pivotally secured to said first cable pull member within said notch for rotation about said second axis. 
     
     
       3. A gearshift as in claim 1 for use where said cable guide means of said bicycle includes a pair of flexible tubular casings which enclose at least a portion of said cables near said free ends of said cables for enabling linear movement of the enclosed cable portions in an arcuate path, said bicycle including means defining fixed points preventing linear movement of first ends of said casings which are located furthest from said free ends of said cables; said gearshift further comprising: said support means defining a first bracket member stationary with said support means and defining an anchorage for a second end of a first one of said flexible tubular casings associated with said first one of said cables;   said first cable pull member defining a second bracket member rotatable with said first cable pull member and defining an anchorage for a second end of a second one of said flexible tubular casings associated with said other one of said cables.   
     
     
       4. A gearshift as in claim 3 wherein said support means defines a pair of lugs spaced apart parallel to each other; wherein said first cable pull member is an elongate member secured to said support means between said lugs for rotation about said first axis, said first cable pull member having first and second end portions at least one of which end portions is cylindrical, said cylindrical end portion being adapted to secure the free end of said first one of said cables and being concentrically rotatable about said first axis for winding said free end of said first one of said cables about said cylindrical end portion of said first cable pull member;   wherein said first cable pull member is provided with a notch defined between first and second end portions of said first cable pull member, said first axis passing through said first and second end portions and across said notch;   wherein said actuator is a lever having a manually graspable upper end portion and having a cylindrical lower end portion defining said second cable pull member and adapted to secure the free end of said other one of said cables;   wherein said second cable pull member is rotatably secured to said first cable pull member within said notch such that said manually graspable upper end portion of said lever is aligned with said first axis for pivotal movability within said first arc axially of said first axis to effect rotation of said second cable pull member about said second axis for winding said other one of said cables about said cylindrical second cable pull member;   wherein said first bracket member depends from said support means between said lugs and is tangentially aligned with said cylindrical end portion of said first cable pull member for guiding the free end of said first one of said cables onto said cylindrical end portion of said first cable pull member; and,   wherein said second bracket member depends from said first cable pull member and is tangentially aligned with said cylindrical lower end portion of said lever for guiding the free end of said other one of said cables onto said second cable pull member.   
     
     
       5. A gearshift for use on a bicycle that has a handlebar, multiple front sprockets mounted on a pedal crank axis, multiple rear sprockets mounted on a rear wheel axis, a roller chain forming a closed loop about and connecting together one each of said front and rear sprockets, a front derailleur and a rear derailleur associated with said front and rear sprockets and movable axially of said pedal crank and rear wheel axes into given front and rear sprocket alignment positions for positioning said roller chain on said front and rear sprockets, respectively, and a pair of cables connected one each to said derailleurs for effecting said axial movement of said derailleurs in response to linear movement of said cables, said bicycle including cable guide means arranged between said derailleurs and free ends of said cables for restricting said cables to linear movement, said cable guide means including a pair of flexible tubular casings which enclose at least a portion of said cables near the free ends of said cables for enabling linear movement of the enclosed cable portions in an arcuate path, said bicycle including means defining fixed points preventing 1 linear movement of first ends of said casings which are located furthest from said free ends of said cables; said gearshift comprising: support means attachable to said handlebar in fixed position and manually rotatable means mounted on said support means defining: a first cable pull member rotatable about a first axis corresponding with a longitudinal axis of said handlebar so as to rotate substantially concentrically with said longitudinal axis of said handlebar, said first cable pull member being adapted to secure the free end of a first one of said cables for effecting linear movement of said first one of said cables by rotation of said first cable pull member about said first axis; and,   a second cable pull member rotatable about a second axis transverse to said first axis, said second cable pull member being adapted to secure the free end of the other one of said cables and effecting linear movement of said other one of said cables by rotation of said second cable pull member about said second axis;   means for holding said first and second cable pull members at rotational settings;   means defining a fixed point preventing linear movement of a second end of the casing associated with said free end of said first one of said cables; and,   means defining a fixed point preventing linear movement of a second end of the casing associated with said free end of said other one of said cables.     
     
     
       6. A gearshift as in claim 5 wherein said second cable pull member defines an actuator having a manually graspable portion pivotable to effect rotation of said second cable pull member about said second axis. 
     
     
       7. A gearshift as in claim 6 wherein said second cable pull member is pivotally secured to said first cable pull member for rotation with said first cable pull member about said first axis, whereby said actuator is pivotable about said second axis to effect rotation of said second cable pull member about said second axis and is also pivotable about said first axis to effect rotation of said first cable pull member about said first axis. 
     
     
       8. A gearshift as in claim 7 wherein said support means defines a first bracket member stationary with said support means for guiding the free end of said first one of said cables onto said first cable pull member, said first bracket member defining said fixed point preventing linear movement of said second end of the casing associated with said free end of said first one of said cables; and wherein said first cable pull member defines a second bracket member rotatable with said first cable pull member about said first axis for guiding the free end of said other one of said cables onto said second cable pull member, said second bracket member defining said fixed point preventing linear movement of said second end of the casing associated with said free end of said other one of said cables.   
     
     
       9. A gearshift as in claim 8 wherein said second axis is perpendicular to said first axis, wherein rotation of said second cable pull member about said second axis is effected by pivotal movement of a manually graspable portion of said actuator within a first arc that is located within a first plane that extends axially of and contains said first axis, and wherein rotation of said first cable pull member about said first axis is effected by pivotal movement of said manually graspable portion of said actuator within a second arc that is located within a second plane that extends axially of and contains said second axis. 
     
     
       10. A gearshift as in claim 9 wherein said actuator defines a yoke receiving said first cable pull member between first and second arms of said yoke, wherein said first and second arms of said yoke are pivotally secured to said first cable pull member for rotation about said second axis and one of said arms of said yoke defines said second cable pull member, and wherein a portion of said yoke located between said first and second arms defines said manually graspable portion of said actuator. 
     
     
       11. A gearshift as in claim 10 wherein said first cable pull member has a length as measured axially of said first axis that is long enough only to enable mounting said actuator and for winding said first one of said cables about said first cable pull member so that said length is short enough to preclude provision of a handhold suitable for manually grasping said first cable pull member for directly twisting said first cable pull member about said first axis. 
     
     
       12. A gearshift as in claim 8 wherein said support means defines a cylindrical sleeve having a longitudinal axis corresponding with said first axis, said sleeve having an inside diameter suitable for mounting said sleeve on said handlebar by receipt of an end portion of said handlebar inside said sleeve, wherein said first bracket member is fixed to one end of said sleeve, wherein said first cable pull member is rotatably mounted on said sleeve near said first bracket member, and wherein said first one of said cables winds onto said first cable pull member at an end of said first cable pull member nearest said first bracket member. 
     
     
       13. A gearshift as in claim 8 wherein said means for holding said first cable pull member at rotational settings comprises said first bracket member including a cylindrical externally threaded portion that is located on a side of said first bracket member facing said first cable pull member and is concentric with said first axis, a manually rotatable correspondingly internally threaded ring mounted on said externally threaded portion of said first bracket member, said sleeve being provided with a groove extending axially of said first axis, and washer means including a tab on an inside diameter of said washer means, said tab being engaged with said groove so as to prevent rotation of said washer means about said first axis but permitting slidable movement of said washer means axially of said first axis, wherein by turning said ring on said threaded portion of said first bracket member said ring is caused to move axially of said first axis and thereby push said washer means into manually adjustable frictional contact with said first cable pull member. 
     
     
       14. A gearshift as in claim 9 wherein said means for holding said second cable pull member at rotational settings comprises: said first cable pull member being provided with a removable pivot member mounted axially of said second axis for pivotal attachment of said end of said yoke defining said second cable pull member, said first cable pull member being provided with an opening for receiving said pivot member, said pivot member having a head portion nonrotatably mounted recessed in an inside wall of said first cable pull member and having a shaft portion of said pivot member extending through said opening and projecting outboard of said first cable pull member, said shaft portion having a smooth portion upon which said second cable pull member is rotatably mounted and having a threaded end portion provided with a groove extending through said threaded end portion axially of said second axis;   second washer means including a second tab on an inside diameter of said second washer means, said second tab being engaged with the groove provided in the threaded end portion of said pivot member so as to prevent rotation of said second washer means about said second axis but permitting slidable movement of said second washer means axially of said second axis; and,   a manually rotatable correspondingly internally threaded second ring mounted on said threaded end portion of said pivot member;   wherein by turning said second ring on said threaded end portion of said pivot member said second ring is caused to move axially of said second axis and thereby push said second washer means into manually adjustable frictional contact with said second cable pull member.   
     
     
       15. A gearshift for use on a bicycle that has a handlebar, multiple front sprockets mounted on a pedal crank axis, multiple rear sprockets mounted on a rear wheel axis, a roller chain forming a closed loop about and connecting together one each of said front and rear sprockets, a front derailleur and a rear derailleur associated with said front and rear sprockets and movable axially of said pedal crank and rear wheel axes into given front and rear sprocket alignment positions for positioning said roller chain on said front and rear sprockets, respectively, and a pair of cables connected one each to said derailleurs for effecting said axial movement of said derailleurs in response to linear movement of said cables, said bicycle including cable guide means arranged between said derailleurs and free ends of said cables for restricting said cables to linear movement, said cable guide means including a pair of flexible tubular casings which enclose at least a portion of said cables near the free ends of said cables for enabling linear movement of the enclosed cable portions in an arcuate path, said bicycle wherein said means defining fixed points preventing linear movement of first ends of said casings which are located furthest from said free ends of said cables; said gearshift comprising: support means attachable to an end portion of said handlebar in fixed position, said support means including a cylindrical sleeve having a longitudinal axis defining a first axis of said gearshift and being adapted for mounting on said end portion of said handlebar substantially concentric with a longitudinal axis of said end portion of said handlebar, said support means further including a first bracket member fixed to one end of said sleeve for mounting on said end portion of said handlebar stationary with said sleeve;   a cylindrical first cable pull member mounted on said sleeve near said first bracket member for concentric rotation about said first axis, said first cable pull member being adapted to secure the free end of a first one of said cables for effecting linear movement of said first one of said cables by rotation of said first cable pull member about said first axis;   an actuator in the form of a yoke having first and second arms of said yoke pivotally secured to said first cable pull member for rotation about a second axis perpendicular to said first axis, a portion of said yoke located between said first and second arms of said yoke defining a manually graspable portion of said actuator and one of said arms of said yoke defining a cylindrical second cable pull member concentrically rotatable about said second axis;   said second cable pull member being adapted to secure the free end of the other one of said cables for effecting linear movement of said other one of said cables by rotation of said second cable pull member about said second axis;   said manually graspable portion of said actuator being pivotally movable within first and second arcs, said first arc being located within a first plane that extends axially of and contains said first axis and when pivotally moved within said first arc said actuator effecting rotation of said second cable pull member about said second axis, and said second arc being located within a second plane that extends axially of and contains said second axis and when pivotally moved within said second arc said actuator effecting rotation of said first cable pull member about said first axis;   means arranged axially of said first and second axes for holding said first and second cable pull members at rotational settings;   said first bracket member being tangentially aligned with said first cable pull member for guiding said first one of said cables onto said first cable pull member and defining a fixed point preventing linear movement of a second end of the casing associated with said free end of said first one of said cables; and,   said first cable pull member defining a second bracket member rotatable with said first cable pull member about said first axis and tangentially aligned with said second cable pull member for guiding said other one of said cables onto said second cable pull member and defining a fixed point preventing linear movement of a second end of the casing associated with said free end of said other one of said cables.   
     
     
       16. A gearshift as in claim 15 wherein said first cable pull member has a length as measured axially of said first axis that is long enough only to enable mounting said actuator and for winding said first one of said cables about said first cable pull member so that said length is short enough to preclude provision of a handhold suitable for manually grasping said first cable pull member for directly twisting said first cable pull member about said first axis. 
     
     
       17. A gearshift as in claim 16 including means for holding said first cable pull member at rotational settings comprises said first bracket member including a cylindrical externally threaded portion that is located on a side of said first bracket member facing said first cable pull member and is concentric with said first axis, a manually rotatable correspondingly internally threaded ring mounted on said externally threaded portion of said first bracket member, said sleeve being provided with a groove extending axially of said first axis, and washer means including a tab on an inside diameter of said washer means, said tab being engaged with said groove so as to prevent rotation of said washer means about said first axis but permitting slidable movement of said washer means axially of said first axis, wherein by turning said ring on said threaded portion of said first bracket member said ring is caused to move axially of said first axis and thereby push said washer means into manually adjustable frictional contact with said first cable pull member. 
     
     
       18. A gearshift as in claim 17 wherein said first one of said cables winds onto said first cable pull member at an end of said first cable pull member nearest said manually adjustable ring. 
     
     
       19. A gearshift as in claim 18 wherein said means for holding said second cable pull member at rotational settings, comprising: said first cable pull member being provided with a removable pivot member mounted axially of said second axis for pivotal attachment of said end of said yoke defining said second cable pull member, said first cable pull member being provided with an opening for receiving said pivot member, said pivot member having a head portion nonrotatably mounted recessed in an inside wall of said first cable pull member and having a shaft portion of said pivot member extending through said opening and projecting outboard of said first cable pull member, said shaft portion having a smooth portion upon which said second cable pull member is rotatably mounted and having a threaded end portion provided with a groove extending through said threaded end portion axially of said second axis;   second washer means including a second tab on an inside diameter of said second washer means, said second tab being engaged with the groove provided in the threaded end portion of said pivot member so as to prevent rotation of said second washer means about said second axis but permitting slidable movement of said second washer means axially of said second axis; and,   a manually rotatable correspondingly internally threaded second ring mounted on said threaded end portion of said pivot member;   wherein by turning said second ring on said threaded end portion of said pivot member said second ring is caused to move axially of said second axis and thereby push said second washer means into manually adjustable frictional contact with said second cable pull member.